NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
| Interpretations | Date |
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ID: aiam5381OpenThe Honorable John A. Boehner Member, United States House of Representatives 5617 Liberty Fairfield Road Hamilton, Ohio 45011; The Honorable John A. Boehner Member United States House of Representatives 5617 Liberty Fairfield Road Hamilton Ohio 45011; "Dear Congressman Boehner: This responds to your letter of April 7 1994, to the Department of Transportation (DOT) on behalf of your constituents, John Cail Sr. and James Lipps of Eaton. Messrs. Cail and Lipps have requested your assistance in obtaining DOT 'approval and color code designation' for their 'Life Lites' system. This is a stop lamp system consisting of two 18-inch long 1/2-inch wide devices intended to be mounted on the front of a vehicle alongside the windshield pillars, to emit a light of either purple or coral. The system is activated with the rear stop lamps when the brakes are applied, and it is intended to warn observers to the front of a vehicle that the vehicle is braking. It 'could be mounted to most existing vehicles and could be readily incorporated into new car designs.' The National Highway Traffic Safety Administration (NHTSA)is the component of DOT that is responsible for motor vehicle safety under the National Traffic and Motor Vehicle Safety Act. The Act does not authorize NHTSA to 'approve' or disapprove safety inventions such as Life Lites. We do advise, however, whether such inventions are permitted under the Act and applicable regulations such as the Federal motor vehicle safety standards. The fact that a device may be permitted under NHTSA laws must not be interpreted as our approval or endorsement of it. The standard that applies to motor vehicle lighting is Standard No. 108 Lamps, Reflective Devices and Associated Equipment. Life Lites emitting either color may be installed as original equipment by the manufacturer, distributor, or dealer at the time a vehicle is sold to its first purchaser provided that it does not impair the effectiveness of any of the frontal lighting equipment required by Standard No. 108 such as headlamps and turn signals. The materials you enclosed show a color closeup newspaper photo of a Life Lite in operation, its relatively low output does not appear sufficient to impair headlamp effectiveness. There would be concern, however, if it were to distract attention from an operating turn signal and, in this sense, impair its effectiveness. However, the responsibility for determining whether supplemental original lighting equipment impairs the effectiveness of the required lighting equipment rests with the installer, and NHTSA will not question this determination unless it appears clearly erroneous. Life Lites that are sold in the aftermarket and intended for vehicles in use, are prohibited by the Act if their installation by a manufacturer, distributor, dealer, or motor vehicle repair business 'knowingly renders inoperative, in whole or part' the required motor vehicle lighting equipment. Though the words are different between the Act and Standard No. 108, in this instance we would equate partial inoperability with impairment of effectiveness and the same considerations would apply. However, the Act does not prohibit vehicle owners under any circumstances from installing Life Lites themselves if they are able to do so. But the legality of Life Lites of either color and under any scenario remains subject to the laws of any State in which the device is operated. We are unable to advise your constituents of the laws of the individual States, and suggest that they write for an opinion to the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, VA 22203. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam5382OpenThe Honorable John A. Boehner Member, United States House of Representatives 5617 Liberty Fairfield Road Hamilton, Ohio 45011; The Honorable John A. Boehner Member United States House of Representatives 5617 Liberty Fairfield Road Hamilton Ohio 45011; Dear Congressman Boehner:: This responds to your letter of April 7 1994, to the Department of Transportation (DOT) on behalf of your constituents, John Cail Sr. and James Lipps of Eaton. Messrs. Cail and Lipps have requested your assistance in obtaining DOT 'approval and color code designation' for their 'Life Lites' system. This is a stop lamp system consisting of two 18-inch long 1/2-inch wide devices intended to be mounted on the front of a vehicle alongside the windshield pillars, to emit a light of either purple or coral. The system is activated with the rear stop lamps when the brakes are applied, and it is intended to warn observers to the front of a vehicle that the vehicle is braking. It 'could be mounted to most existing vehicles and could be readily incorporated into new car designs.' The National Highway Traffic Safety Administration (NHTSA)is the component of DOT that is responsible for motor vehicle safety under the National Traffic and Motor Vehicle Safety Act. The Act does not authorize NHTSA to 'approve' or disapprove safety inventions such as Life Lites. We do advise, however, whether such inventions are permitted under the Act and applicable regulations such as the Federal motor vehicle safety standards. The fact that a device may be permitted under NHTSA laws must not be interpreted as our approval or endorsement of it. The standard that applies to motor vehicle lighting is Standard No. 108 Lamps, Reflective Devices and Associated Equipment. Life Lites emitting either color may be installed as original equipment by the manufacturer, distributor, or dealer at the time a vehicle is sold to its first purchaser provided that it does not impair the effectiveness of any of the frontal lighting equipment required by Standard No. 108 such as headlamps and turn signals. The materials you enclosed show a color closeup newspaper photo of a Life Lite in operation, its relatively low output does not appear sufficient to impair headlamp effectiveness. There would be concern, however, if it were to distract attention from an operating turn signal and, in this sense, impair its effectiveness. However, the responsibility for determining whether supplemental original lighting equipment impairs the effectiveness of the required lighting equipment rests with the installer, and NHTSA will not question this determination unless it appears clearly erroneous. Life Lites that are sold in the aftermarket and intended for vehicles in use, are prohibited by the Act if their installation by a manufacturer, distributor, dealer, or motor vehicle repair business 'knowingly renders inoperative, in whole or part' the required motor vehicle lighting equipment. Though the words are different between the Act and Standard No. 108, in this instance we would equate partial inoperability with impairment of effectiveness and the same considerations would apply. However, the Act does not prohibit vehicle owners under any circumstances from installing Life Lites themselves if they are able to do so. But the legality of Life Lites of either color and under any scenario remains subject to the laws of any State in which the device is operated. We are unable to advise your constituents of the laws of the individual States, and suggest that they write for an opinion to the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, VA 22203. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1913OpenMr. Danny J. Lanzdorf, Supervising Engineer, Oshkosh Truck Corporation, P.O. Box 560, Oshkosh, WI 54901; Mr. Danny J. Lanzdorf Supervising Engineer Oshkosh Truck Corporation P.O. Box 560 Oshkosh WI 54901; Dear Mr. Lanzdorf: This responds to your April 1, 1975, request for confirmation that th emergency braking stopping distance requirements in S5.7.2.3 of Standard No. 121, *Air brake systems*, specify that, when stopped six times for each configuration of weight and speed specified in S5.3.1.1 on a road surface with a skid number of 75 (with a single failure introduced in the service brake system), the vehicle must stop at least once within the distances specified in Column 3 of Table II and no part of the vehicle must leave the 12-foot roadway. You also request confirmation that modulation of the service brake control during the stop is not prohibited.; With certain exceptions, the statements in your letter are correct Your interpretation only sets out the basic stopping distance requirements for those vehicles which the manufacturer has chosen to make conform to S5.7.2 of the standard. Thus, your interpretation does not include any of the requirements of the emergency braking capability option found in S5.7.1. Additionally, your interpretation does not include the requirements for a truck-tractor at unloaded vehicle weight plus 500 pounds, or for the trucks and buses which qualify for the interim requirements of S5.7.2.3.1 and S5.7.2.3.2.; Section S5.7.2 does not prohibit modulation of the emergency brakin capability, and modulation by means of the service brake control is therefore permissible.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3397OpenMr. Norman B. Echelberry, 2514 Sherman Street, Hollywood, FL 33020; Mr. Norman B. Echelberry 2514 Sherman Street Hollywood FL 33020; Dear Mr. Echelberry: This is in response to the vehicle owner's questionnaire you forwarde on March 9, 1981, concerning the installation of computer terminals in patrol cars assigned to the city of Miami Police Department. The questionnaire was recently forwarded to my office for reply. You asked whether the installation violated any safety standards.; Federal Motor Vehicle Safety Standard No. 201, *Occupant Protection i Interior Impact*, a copy of which is enclosed, specifies performance requirements for the instrument panel. It can't be determined from the information you provided whether the terminals are located within an area of vehicle covered by that standard. The standard generally regulates only the upper portion of the dashboard. If it is located within the regulated zone, the installation of the computer terminal on the vehicle's instrument panel may be affected by section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A). That section provides that:; >>>No manufacturer, distributor, dealer or motor vehicle repai business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard....<<<; Modification of the instrument panel by a manufacturer, distributor dealer or motor vehicle repair business during the installation of the computer terminals so that it no longer complies with Standard No. 201 would be a violation of section 108(a)(2)(A).; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2037OpenMr. Robert L. Donnelly, Secretary, Armstrong Rubber Company, New Haven, Connecticut 06507; Mr. Robert L. Donnelly Secretary Armstrong Rubber Company New Haven Connecticut 06507; Dear Mr. Donnelly: This responds to your letter of may 30, 1975, concerning the standard applicable to a tire which you manufacture and sell with the designation L78-15LT, Load Range C.; You are mistaken in your assumption that a station wagon is classifie as a multi-purpose passenger vehicle. Because it is constructed neither on a truck chassis nor with special features for occasional off-road operation, a station wagon is a passenger car rather than a multi-purpose passenger vehicle.; If, despite this misunderstanding, the L78-15t tire is question i designated by you as primarily intended for use on lightweight trucks or multi-purpose passenger vehicles, the it is a light truck tire subject to Federal Motor Vehicle Safety Standard No. 119, *New Pneumatic Tires for Vehicles Other than Passenger Cars*.; Because a station wagon is a passenger car, Standard No. 110 require that its original equipment tires comply with standard No. 109. Standard No. 110 is not applicable to used cars, so there is no prohibition on the use of the L78-15LT tire as replacement equipment on a station wagon. However, because the informational placard on a station wagon would suggest its owner the use of inflation pressures which are dangerously inadequate for light truck tires, we do not wish to encourage the sale of such tires as replacement equipment for use on station wagons.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam4713OpenMr. Bill Waltz Wagner Division Cooper Industries, Inc. 155 Algonquin Parkway Whippany, NJ 07981; Mr. Bill Waltz Wagner Division Cooper Industries Inc. 155 Algonquin Parkway Whippany NJ 07981; Dear Mr. Waltz: This is in reply to your letter requesting permissio for deviations from marking requirements for round sealed beam headlamps. Wagner has been asked to assemble some headlamps designed to appear as closely as possible to those produced by Guide Lamp in the l950's. The lamps would be marked 'l' and '2' in accordance with the nomenclature of the day, rather than '2Dl', '1C1', and '2C1', as required by Standard No. 108. The DOT symbol would not be provided, 'since this obviously was not on the original lamps.' You have informed us that the lamps 'will be made to today's photometric standards' and 'subjected to all the tests currently required of the round headlights.' Finally, 'they will be distributed on a limited basis through antique parts dealers.' I am sorry, but we have no authority to exempt manufacturers of motor vehicle equipment from any requirements of the Federal motor vehicle safety standards. Our temporary exemption authority under l5 U.S.C. 1410 extends only to motor vehicles. Further, we have no authority to exempt manufacturers of either vehicles or equipment from their statutory obligation to certify through use of the DOT symbol that their products meet all applicable Federal motor vehicle safety standards. Under Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment, the motor vehicle lamps which you have identified, and for which you ask an exemption are designated Type C and Type D sealed beam headlamps. As such, they must be designed to conform to the photometric requirements of SAE Standard J579c, December l978, which are incorporated by reference in Standard No. 108. They are considered replacement equipment, and must conform to all requirements of Standard No. 108, including marking and certification. Standard No. 108 covers both original and replacement vehicle equipment. Depending on the vehicle category, it became effective for original equipment on January 1, l968, and January 1, l969. On January 1, l972, it became effective for equipment intended to replace original equipment on all motor vehicles manufactured on and after January 1, l972. Therefore, it might appear that the standard would not apply in any event to replacement equipment for l950's vehicles. However, the headlamps you describe are designed to conform to all contemporary requirements, except marking and certification. Even though intended for use on l950's vehicles, these circular headlamps are interchangeable with circular headlamps installed on any vehicle manufactured after the effective dates of Standard No. 108. Therefore, they must be designed to conform with Standard No. 108, and marked and certified accordingly. The intended markings 'l' and '2' would signify mistakenly that the headlamps were designed to conform to SAE Standard J579a, October l965 (which also did not require the DOT symbol on the lens). Until June l989, SAE J579a was incorporated in Standard No. 108 as a permissible option to SAE J579c, but the agency deleted it as the lamps appeared to be out of production. However, even had J579a been retained, we could not have allowed the lenses of headlamps manufactured to J579c to be marked according to J579a. Sincerely, Stephen P. Wood Acting Chief Counsel /; |
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ID: aiam4517OpenMr. Peter Cameron-Nott 90 Horace Street Stratford, CT 06497; Mr. Peter Cameron-Nott 90 Horace Street Stratford CT 06497; Dear Mr. Cameron-Nott: This is in reply to your letter of June 1, 1988 with reference to importation of motor vehicle equipment included in an incomplete vehicle. You have stated that the kit will include brake hoses, brake fluid, and glazing, and that these items will conform with Motor Vehicle Safety Standards Nos. 106, 116, and 205 respectively, and that they will all carry the DOT symbol certifying compliance. You ask whether these items may be entered under Box 2 on the HS-7 importation form. The answer is yes. Box 2 (implementing l9 C.F.R. 12.80(b)(l)(ii)) allows importation without bond of motor vehicles and equipment manufactured to conform with, and certified as conforming to, all applicable Federal motor vehicle safety standards. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam5569OpenThomas L. Wright, Acting Manager MVS Customer Services State of New Jersey Department of Law and Public Safety Division of Motor Vehicles Trenton, NJ 08666; Thomas L. Wright Acting Manager MVS Customer Services State of New Jersey Department of Law and Public Safety Division of Motor Vehicles Trenton NJ 08666; "Dear Mr. Wright: This responds to your request for information abou responsibilities of motorcycle manufacturers. As you discussed with Dorothy Nakama, the National Highway Traffic Safety Administration (NHTSA) does not 'regulate' how an enterprise becomes a 'recognized manufacturer.' Enclosed is NHTSA's information sheet for new manufacturers of motor vehicles and motor vehicle equipment, which discusses the main requirements of 49 U.S.C. section 30101 et seq. (formerly the Vehicle Safety Act). A copy of the Act is enclosed. Under section 30112(a) of the Act, a motorcycle manufacturer may not manufacture a motorcycle for sale unless the vehicle complies with all applicable Federal Motor Vehicle Safety Standards (FMVSS) and is covered by a certification issued under 49 U.S.C. section 30115. One safety standard is Standard No. 115 Vehicle Identification Number - Basic Requirements. (See 49 CFR 571.115.) In our regulations, at 49 CFR part 567 Certification, NHTSA has promulgated the requirement that a manufacturer certify compliance of its motorcycle with all applicable safety standards. Under part 566, NHTSA requires manufacturers to submit certain identifying information and a description of the items they produce. Also enclosed is a copy of a July 13, 1992 interpretation letter to Mr. Jeffrey Puentes, discussing serial numbers on motorcycle frames versus motorcycle VINs. As you may be aware, 'certificates of origin' are matters relating to vehicle titling, which the State regulates, rather than NHTSA. I hope this information is helpful. If you have any further questions, please contact Ms. Nakama at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures"; |
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ID: aiam3362OpenMr. Mark Lundin, Services Coordinator, Interregional Services Corporation, 2021 East Hennepin Avenue, Minneapolis, MN 55413; Mr. Mark Lundin Services Coordinator Interregional Services Corporation 2021 East Hennepin Avenue Minneapolis MN 55413; Dear Mr. Lundin: This is in response to your letter of September 5, 1980, asking whethe there is a Federal bumper standard applicable to trucks, and who is responsible for installation of the rear bumper on a truck manufactured in two or more stages. You also inquire whether a truck without a rear bumper is considered a completed vehicle for purposes of Federal regulations, and whether a truck with a frame rail extending beyond the rear end of the vehicle body would violate Federal standards.; The Part 581 Bumper Standard (49 CFR Part 581) applies only t passenger motor vehicles other than multipurpose passenger vehicles. Thus, there is no Federal bumper standard applicable to trucks, and Federal regulations do not impose responsibility for bumper installation on any party in the chain of manufacture.; Part 568, Vehicles Manufactured in Two or More Stages, define 'completed vehicle' as a vehicle that requires no further manufacturing operations to perform its intended function, other than the addition of readily attachable components (49 CFR S 568.3). Since the vehicle referred to in your letter apparently is capable of performing its intended function without addition of a bumper, the absence of a bumper would not be relevant in determining the vehicle's final-stage manufacturer for purposes of compliance and certification of compliance with Federal motor vehicle safety standards (49 CFR SS 567.5 and 568.6).; At the present time, there are no Federal standards which prohibit th extension of a frame rail beyond the rear end of a truck body. However, the National Highway Traffic Safety Administration is considering proposal of a regulation which would require protective devices to reduce vehicle penetration under the rear ends of heavy trucks and trailers.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1176OpenMr. Krish Kudva, Manager, Philips Industries Inc., 4801 Springfield Street, Dayton, OH 45401; Mr. Krish Kudva Manager Philips Industries Inc. 4801 Springfield Street Dayton OH 45401; Dear Mr. Kudva: This is in reply to your letters of June 4 and June 22, 1973 concerning Federal Motor Vehicle Safety Standard No. 205, 'Glazing Materials'. Your letter of June 4 asks which glazing materials may properly be used in motor homes under the Federal standard, and whether State laws which provide otherwise are invalid under the National Traffic and Motor Vehicle Safety Act. Your letter of June 22 asks what requirements apply for glazing materials used in travel trailers.; Our records indicate that we wrote on July 5, 1972, to Mr. Robert T Sanders of Philips Industries, in response to a letter from him concerning glazing requirements for chassis-mount and slide-in campers, trailers, and motor homes. Standard No. 205 has been amended since that date (on November 11, 1972, 37 FR 24035) and this letter reflects some of the changes in the standard made by that amendment.; The requirements for glazing for use in motor homes, which under NHTS definitions now includes chassis-mount campers as well as traditional motor homes, are essentially those specified in ANS Z26 for trucks, with certain exceptions. Thus, for windshields, AS 1 or AS 10 materials may be used. For windows to the immediate right and left of the driver, AS 1, AS 2, AS 10, and AS 11 materials may be used, and AS 3 may be used in the unusual situation where any such window is not requisite for driving visibility. All other windows may be AS 1, AS 2, AS 10, AS 4, and AS 8 materials. Additionally, windows other than windshields and those to the immediate right and left of the driver may be: AS 3, AS 5, AS 9, and AS 12 where not requisite for driving visibility, AS 6 where not forward- facing, AS 7 and AS 12 where neither at levels requisite for driving visibility nor forward-facing.; I would add that the term 'forward-facing' is not limited t windshields or behind-the-cab windows, as your letter implies, but applies to any window that is mounted in a plane transverse to the longitudinal centerline of the vehicle. It includes as well, for example, windows placed above the windshield, and any transverse interior partition.; Section 103(d) of the National Traffic and Motor Vehicle Safety Act (1 USC 1392(d)) does prohibit, as you indicate in your letter, any State or political subdivision of a State from establishing or continuing in effect with respect to a motor vehicle or item of motor vehicle equipment any safety standard applicable to the same aspect of performance of the vehicle that is not identical to the Federal standard. The question raised by your letter is whether a State law which prohibits the use of glazing materials in locations of motor vehicles where they are specifically permitted to be used by the Federal standard is violative of section 103(d). It is our view that such a law is violative of section 103(d), and is invalid, as we believe that the use of a particular glazing material in specific vehicle locations is an aspect of performance that is covered by Standard No. 205. You are correct in adding, however, that under section 103(d) a State (or subdivision thereof) may require a higher standard of performance than that established by the Federal standard in vehicles or items of motor vehicle equipment procured for its own use. You may, of course, refer to this letter in your discussions with any State authorities regarding these issues.; The interpretation in your letter of June 22 that Standard No. 205 doe not apply to glazing materials for use in travel trailers is correct.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.